Browse the evidence

Most dietary (poly)phenols are not absorbed intact in the small intestine but pass to the colon where gut microbiota catabolize them into absorbable metabolites, which then enter circulation and exert biological effects.

Eat a variety of plant-based foods rich in polyphenols (berries, tea, coffee, onions, citrus). You do not need to worry about the 'bioavailability' of the raw compound because your gut bacteria process them into active metabolites that enter your bloodstream. The specific benefits depend on your unique gut microbiome, so diversity in your diet helps ensure you have the right bacteria to process different polyphenols.

Current anti-obesity medication (AOM) studies frequently misrepresent skeletal muscle mass (SMM) loss by using DXA or BIA to estimate fat-free mass (FFM) or lean mass, which includes bone and non-skeletal tissues, thereby confounding the assessment of clinically significant muscle loss.

When reading studies on weight loss drugs (like GLP-1 agonists) that report 'muscle loss' based on DXA or bioimpedance scales, recognize that these numbers likely overestimate true skeletal muscle loss because they include bone and water. True muscle loss is likely lower than reported in these specific studies. Look for studies using MRI or CT for accurate skeletal muscle quantification.

Post-weigh-in rehydration should involve consuming 125-150% of lost body mass in fluids containing specific electrolytes (1700mg Na, 800mg K, 2300mg Cl, 13g CHO per liter) to maximize absorption and retention.

After weigh-in, drink fluids containing sodium, potassium, chloride, and carbs (like a sports drink or ORS). Drink 125-150% of the weight you lost. Start with 750-1000mL right away, wait 30 minutes, then eat a small, digestible meal with 50-100g carbs. Continue drinking at 1-1.5 liters per hour.

Patients using GLP-1 receptor agonists (GLP-1RA) for weight loss consistently fail to meet Dietary Reference Intakes (DRI) for key micronutrients (fiber, calcium, iron, magnesium, potassium, choline, vitamins A, C, D, E, K) and MyPlate food group servings (fruit, vegetables, grains, dairy).

If you are taking a GLP-1RA, your reduced appetite likely means you are not getting enough fiber, calcium, magnesium, and vitamins. You must actively track your food intake to ensure you are hitting micronutrient goals, as you cannot rely on feeling full. Focus on nutrient-dense foods and consider supplementation if dietary intake remains low, as standard portion sizes are likely insufficient.

Vitamin D supplementation can suppress myostatin expression and stimulate anabolic pathways (Akt/mTOR, IGF-1), potentially aiding muscle preservation in at-risk populations.

If you are elderly or have a chronic condition, ensuring adequate Vitamin D levels may help support muscle health by influencing myostatin and anabolic pathways. Consult your doctor for appropriate dosing, as thresholds are not yet defined.

Oral supplementation with a specific ratio of three amino acids (3 Glycine : 1 Proline : 1 Hydroxyproline), combined with Vitamin C, astaxanthin, and alpha-ketoglutarate, reduces biological age by approximately 1.4 years in humans over a 6-month period and improves skin texture, hydration, and elasticity within 1-3 months.

Take a daily supplement containing a 3:1:1 ratio of Glycine, Proline, and Hydroxyproline, combined with Vitamin C, Astaxanthin, and Alpha-Ketoglutarate. This specific combination was shown to improve skin texture, hydration, and elasticity within 1-3 months, and reduce biological age by about 1.4 years over 6 months in a clinical trial. It is generally safe, though a small percentage of users may experience mild side effects like rosacea or intestinal reactions.

Biathletes should monitor iron and vitamin D levels, as deficiencies are common in endurance sports and can impair performance and health, even if general micronutrient deficiencies are less common in biathletes due to high caloric intake.

Get your iron and vitamin D levels checked regularly. If you are deficient, supplement as directed by your healthcare provider. Focus on iron-rich foods (meat, fish, legumes) and vitamin D sources (sunlight, fortified foods, or supplements if needed).

Leucine supplementation (50 mg/kg/day) significantly improves sprint performance in basketball athletes by enhancing cytoskeletal dynamics and muscle adaptation.

Basketball players looking to improve sprint speed may benefit from taking 50 mg of leucine per kg of body weight daily, split before and after training, for at least 4 weeks. This should be combined with a balanced diet and regular training. While shooting accuracy showed trends, the strongest evidence supports speed improvements.

Leucine supplementation upregulates cytoskeletal genes (e.g., tubulins, vimentin, cadherins) in muscle tissue, which may support muscle growth and structural integrity.

For coaches and athletes, the upregulation of cytoskeletal genes suggests that leucine may help build more resilient muscle tissue. This supports the use of leucine not just for immediate performance, but for long-term muscle health and recovery in high-intensity sports.

Whey protein powders contain significantly higher concentrations of sweet-tasting free amino acids (glycine, alanine, serine, proline, threonine) compared to plant-based protein powders.

If you are choosing between whey and plant protein, be aware that whey naturally contains higher levels of certain free amino acids like glycine and alanine. This difference exists regardless of the total protein content listed on the label.

High concentrations of specific free amino acids (glutamine, tryptophan) are consistently present in both whey and plant-based protein powders.

You can expect both whey and plant protein powders to be rich sources of glutamine and tryptophan.

The geographical origin of protein powder (India, China, Japan) significantly influences its free amino acid profile.

The country where your protein powder was manufactured affects its specific amino acid content, not just the brand or type.

Correcting vitamin D insufficiency (levels < 30 ng/mL) may be warranted to prevent greater quadriceps muscle loss and support genomic recovery processes after ACL reconstruction.

Have your Vitamin D levels checked after ACL surgery. If they are below 30 ng/mL, correcting this insufficiency may help reduce quadriceps muscle loss and support recovery, though its impact on functional outcomes is less clear.

Consuming whole dairy milk provides superior nutrient bioavailability and fewer adverse metabolic effects compared to isolated dairy nutrients or high-dose supplements due to the protective food matrix.

Prioritize drinking plain cow's milk over calcium supplements or isolated whey powders when possible. The natural structure of milk helps your body absorb nutrients better and avoids potential side effects linked to high-dose isolated supplements.

Fermented dairy products offer enhanced health benefits compared to unfermented milk due to bioactive compounds produced during fermentation and reduced lactose content.

If you experience bloating or discomfort from milk, try fermented options like yogurt or kefir. The fermentation process breaks down lactose and creates beneficial compounds that support gut health.

Specific micronutrients (folate, choline, resveratrol, EGCG) can mitigate toxin-induced epigenetic damage by altering DNA methylation and histone modification patterns.

Ensure adequate intake of methyl-donors (folate, choline, B vitamins) and antioxidants (resveratrol, EGCG) to help mitigate the epigenetic damage caused by environmental toxins like smoke and alcohol.

GLP-1 receptor agonist (GLP-1RA) therapy is associated with clinically relevant risks of protein, vitamin, and mineral deficiencies due to reduced caloric and nutrient intake.

If you are taking a GLP-1 medication like semaglutide or tirzepatide, you are likely eating less, which means you might not be getting enough vitamins and minerals. You should prioritize nutrient-dense foods and discuss baseline blood testing for Vitamin D, B12, Iron, and Calcium with your doctor. Do not assume that because this is a medication and not surgery, you are exempt from nutritional monitoring.

Zinc supplementation (50 mg oral zinc acetate, 2x/day for 14 weeks) improves insulin secretion specifically in individuals with the SLC30A8 rs13266634 CT/TT genotype, demonstrating a genotype-dependent response to micronutrient intervention.

If you are considering zinc supplementation for insulin resistance, check your SLC30A8 genotype first. If you carry the CT or TT variant of rs13266634, 50mg of zinc acetate twice daily for 14 weeks may significantly boost your fasting insulin levels. If you have the CC genotype, this specific intervention may not offer the same benefit.

Multivitamin supplementation is recommended for individuals using GLP-1 receptor agonists to address micronutrient insufficiencies resulting from reduced caloric intake and gastrointestinal side effects.

Take a daily multivitamin while on GLP-1RA medication. Because you are eating less, you might not get enough vitamins from food alone. This helps protect your long-term health and prevents deficiencies.

Carbohydrate reduction leads to a significant decrease in Alanine Aminotransferase (ALT) levels, indicating improved liver function, while HDL cholesterol may show a small decline.

Your liver function is likely to improve, as shown by a significant drop in ALT levels. However, be aware that HDL ('good') cholesterol may decrease slightly. This is a common finding with carbohydrate reduction and should be monitored by your doctor.

Second-generation incretin-based therapies (semaglutide, tirzepatide) increase the risk of micronutrient deficiencies and related complications, primarily through reduced dietary intake and altered food selection, with real-world data showing a 22.4% incidence of recorded nutritional deficiencies at 12 months.

If you are taking semaglutide or tirzepatide, your reduced food intake may lead to micronutrient gaps. Prioritize nutrient-dense foods (vegetables, lean proteins, dairy) and consider discussing baseline testing (Vitamin D, B12, Iron) with your doctor, especially if you experience GI side effects or rapid weight loss.

Synbiotics (combining probiotics and prebiotics) improve the survival and efficacy of probiotics in the gastrointestinal tract compared to probiotics alone.

If you take probiotics, consider a synbiotic formulation that includes prebiotics (like oligosaccharides). This combination helps the probiotic bacteria survive stomach acid and colonize the gut more effectively.

Omega-3 fatty acid supplementation does not significantly alter ALT levels in individuals with MASLD.

Taking Omega-3 fatty acid supplements does not significantly lower liver enzymes (ALT) in people with MASLD compared to control groups. While Omega-3s are generally healthy, they should not be relied upon as a primary treatment for improving liver health biomarkers in this condition.

Specific fatty acid esters of hydroxy fatty acids (FAHFAs), particularly 5-PAHSA and 9-PAHSA, improve insulin sensitivity and glucose-stimulated insulin secretion.

Research shows that specific fatty acid derivatives called FAHFAs (like 5-PAHSA) can improve how your body handles insulin and glucose. However, this is currently based on animal studies and human observational data, not proven clinical treatments. Do not self-prescribe specific isomers until more clinical trials are available.